Chromonychia:Pigmented Nail

Disorders

Nail Anatomy Nail plate – actual nail made of

tightly packed onychocytes; DIPJ in close proximity.

Proximal Nail Fold Cuticle Nail Matrix – Epithelium beneath

nail plate; longitudinal grooves (melanoma, splinter hemorrhage); splinter hemorrhage-endocard trichinosis, trauma, PS, vasculitis)

Hyponychium – epithelum on volar surface of digit

Lunula – visible portion of distal matrix

Lateral digital artery

Nail Anatomy Continued Proximal portion of nail matrix gives rise to dorsal

nail plate Distal portion of nail matrix produces the ventral

nail plate Proximal matrix >> pitting(paraker),

onychorrhexis, beau’s lines Mid-matrix >> leukonychia Distal Matrix .. Onycholysis, thinned nail plate,

erythema of the lunula Melanocytes more numerous in distal nail matrix

than proximal (melanonychia)

Nail Embryology Matrix appears at 10 weeks as a wedge

of basal like cells (matrix primordium) Earliest nail plate at 14 weeks Full nail at 17 weeks

Why do we have nails? Protects the fingertips and toes Fine touch/increases tactile sensitivity Essential for picking up small objects Toenails – contribute to foot

biomechanics

Nail Growth Rates Fingernails – 3mm/month; replacement = 6

months Toenails – 1mm/month; replacement = 12 – 18

months Faster Growth Rates – Psoriasis, males, youth,

onycholysis, summer, periungual inflammation, onychophagia, day, premenstrual, pregnancy, hyperthyroids handedness.

Slower growth rates: thumb and 5th finger, viral disease/fever, chemo, immobilization, poor nutrition, yellow nail syndrome

Acquired Melanonychia

Acquired Melanonychia

80 year old woman presented with longitudinal melanonychia, or longitudinal dark pigmentation of the nails

Noticed the pigmentation after a year since the start of hydroxyurea treatment for essential thrombocythemia

Case Presentation

Case Presentation (Continued) Patient had no other side effects, no

other hyperpigmentation, and was not taking any other medications that would have caused nail changes.

So how did this happen?

Hydroxyurea Therapy Hydroxyurea is used to treat a certain type of chronic

myelogenous leukemia It is also used to treat ovarian cancer, melanoma, and

certain types of head and neck cancer (including cancer of the mouth, cheek, tongue, throat, tonsils, and sinuses).

Hydroxyurea is also used to reduce the frequency of painful crises and reduce the need for blood transfusions in patients with sickle cell anemia

Hydroxyurea treats cancer by slowing or stopping the growth of cancer cells in your body. Hydroxyurea treats sickle cell anemia by helping to prevent formation of sickle-shaped red blood cells.

So what does this have to do with Melanonychia????

Well... Melanonychia is a rare SIDE EFFECT of

hydroxyurea therapy The differential diagnosis includes:

Subungal melanoma Pigmented squamous cell carcinoma Subungal hematoma Nevus Hyperpigmentation due to other drugs

Cyclophosphamide, doxorubicin, minocycline, and zidobudine

Mechanism of Hydroxyurea Therapy Hydroxyurea can cause a severe decrease

in the number of blood cells in your bone marrow

However, the mechanism of hydroxyurea – induced melanonychia is UNKNOWN.

Potential causes include: Toxicity affecting the nail bed or nail matrix Focal stimulation of nail matrix melanocytes Photosensitization

What is Melanonychia

Melanin within the nail plate is usually produced by nail matrix melanocytes

Active melanocytes transfer melanin-rich melanosomes by the way of dendrites to differentiating nail matrix-derive onychocytes

This can lead to a longitudinal streak along the nail plate

Other Causes of Melanonychia

Melanonychia is an ambiguous clinical finding that occurs as a result of benign etiologies: Nail matrix melanocytic activation Nail matrix melanocytic hyperplasia Nail invasion by melanin producing pathogens

Other nail pathogens can cause NON – MELANIC brown – to – black nail pigmentation Exogenous substances Subungal hemorrhage Trauma Vitamin Deficiencies

How to Evaluate Melanonychia

NAIL MATRIX SHAVE BIOPSY!!!!

Nail plate clipping can be sent for histological evaluation or histological analysis

Examination of affected nails w/a dermatoscope

Hutchinson sign – a sign of subungal melanoma, however it is not the best predictor of disease!

Treatment of Melanonychia Depends on the etiology

Discontinue medication/therapy! Multivitamins Time Last two are if problem is not

melanonychia, but rather an outcome of another etiology.

See a Dermatologist

Green Nails

Introduction A 53 year old intensive care nurse being

treated with efalizumab for psoriasis involving her arms, legs and nails.

After a few weeks of treatment the patient started to develop a strange discoloration of both thumbnails.

Oh my…

Diagnosis After careful bacteriologic examination

of the nail scrapings it was determined that the strange discoloration was caused by Pseudomonas aeruginosa and Klebsiella pneumoniae.

Both organisms were shown to be sensitive to fluoroquinolone

Pseudomonas aeruginosa A Gram negative, aerobic,

coccobacillum bacterium Commonly found in moist dwellings P. aeruginosa secretes a variety of

pigments, including pyocynanin, pyoverdin, and pyorubin.

Pathomechanics of Infection Psoriasis-induced onycholysis Patient may have acquired when

gardening or at work in the hospital. Frequent hand washing may have

created a moist environment for infection.

Treatment 2 week course of topical Nadifloxacin

Others..Mainly due to obvious cosmetic procedures, topical or oral drugs, or common diseases. None is of particular significance in itself, its presence sometimes aiding in the diagnosis of disease or pointing towards overdose of drugs.

White Nail (Leukonychia) Most common color change Two types, but techincally three

True leukonychia, nail plate involvement Diffraction of light in abnormal keratotic cells

Apparent leukonychia with subungal tissue involvement Underlying onycholysis and subungal hyperkeratosis Modification of matrix and or nail bed

Pseudoleukonychia, fungal infection involves nail plate

White Nail (Leukonychia) cont.. Causes:

Congenital and or hereditary Isolated, acrokeratosis, psoriasis, etc.

Acquired Pseduoleukonychia Diffuse distal and lateral subungual onychomycosis, superficial

white onychomycosis, keratin granulation, etc.

Apparent leukonychia Anaemia, cancer chemotherapeutic agents, Cirrhosis, Leprosy,

etc. True leukonychia

Alkaline metabolic disease, alopecia areata, Gout, Hodgkin’s disease, Occupational, Sickle cell, Tumors, etc.

Yellow Nail Nail enamle and hardeners AIDS Carotene Dermatophyte onychomycosis Drugs

Tetracycle fluorsecent lunula Penicillamine Clioquinole (topical) Mepacrine (nail bed) Jaundice

Blue/Blue-Grey Nail Antimalarials Argyria Bleomycin Congenital Pernicious anaemia Minocycline Phenolphthalein Phenothiazines Wilson’s disease

Red/Purple Angioma Cirsoid aneurysm tumour Glomus tumor Congestive cardiac failure (lunula) Enchondroma Heparin Lichen planus Linear red line

Darier’s disease Benign tumours/cysts near proximal matrix

Lupus erythematosus Porphyria (with fluorescence) Rheumatoid arthritis Warfarin

Citations Baran, R., Julian Barth, and R. P. R. Dawber. Nail

Disorders: Common Presenting Signs, Differential Diagnosis, and Treatment. New York: Churchill Livingstone, 1991. Print.

Stern, Dana. "Nail Disorders." Dermatology Lecture. The New York College of Podiatric Medicine, New York. 07 Feb. 2013. Lecture.

Ranta, Dana MD and Bonmati, Caroline MD. Acquired Melanonychia. New England Journal of Medicine 2009; 361:1188 September 17, 2009.

Hengge, Ulrich R. MD and Bardeli, Virginia MD; Green Nails New England Journal of Medicine March 12, 2009

Now you’re ready to “nail” nail pathology!